Question: Evaluate the following expression when $x = 5$ and $y = 1$. $7$ $x$ $ + 9$ $y$ $ - 9$
Solution: Substitute $5$ for ${x}$ and $1$ for ${y}$ $ = 7{(5)} + 9{(1)} - 9 $ $ = 35 + 9 - 9 $ $ = 35$